1. Field of the Invention
The present invention relates generally to optical readers, and particularly to optical readers employing imagers.
2. Technical Background
Optical indicia readers equipped to read one-dimensional or two-dimensional bar code symbols are well known in the art. There are a number of optical character recognition systems on the market as well. In addition, many financial institutions today employ computer-driven signature capture systems. Many of these systems employ monochrome imagers because monochrome imagers are well-suited to read graphical symbols, such as bar codes, OCR symbols, or signatures.
On the other hand, the ability to provide image capture functionality along with indicia reading in one device is very appealing. Currently, optical readers having image capture functionality use monochrome imagers that provide gray scale images. While such devices are useful, gray scale images are less desirable than color images for viewing purposes. The public has come to expect color imaging. Further, monochrome images are often less distinct and not as informative as color images.
Unfortunately, there are problems associated with using color imaging systems to read graphical symbols. The first problem relates to the difficulty of distinguishing bi-tonal indicia in a color image. Because color imagers provide more information that bi-tonal indicia readers can use, color imaging data is often confusing to graphical symbol indicia readers. One way to solve this problem is to convert the color imaging data into gray-scale data. However, commercially available methods for converting color images to gray-scale are too slow for high-volume scanning. Thus, an optical reader employing a color imager with a gray scale converter would be slower and more expensive than an optical reader using monochrome imager because of the additional processing required.
Thus, a need exists for an inexpensive optical reader that is capable of performing color photography and evaluating graphical symbols. This optical reader must be capable of automatically determining whether an image includes a graphical symbol or is merely a color photographic image, and process the acquired color imaging data based on that determination. A need also exists for an optical reader that is able to associate an acquired color image with any subsequent acquired color image.